This invention relates to a ball bearing for longitudinal movements of a cylindrical shaft with ball races, which in themselves are closed and distributed about the circumference of the bearing. The ball bearing has an outer shell or sleeve with longitudinal load sections, which are distributed about the circumference of the bore of the outer shell, and with depression or return race sections, which are arranged between the load sections. In addition, the ball bearing has a bearing cage, which guides the balls and which is mounted in the bore of the outer shell in such a manner that it can rotate.
The state of the art includes a ball bearing in which the balls of each ball race, that are under load, run on different surface lines of the longitudinal sections, the surface lines being inclined at an angle. Because of unrestricted rotation of the bearing cage in operation, the balls under load roll laterally from their longitudinal sections into the connecting depression or return grooves in the bore of the outer shell, where the load is removed from them. In a similar manner, the balls of each ball race, which are not under load, run, through rotation of the bearing cage, to the respective longitudinal section in the bore of the outer shell, where they are placed under load. It is a serious disadvantage of this ball box, that the load is removed intermittently from the balls as they enter laterally into the depression section, and that the load is applied intermittently as they enter onto the longitudinal section; the consequence is that the balls and races are stressed excessively and damaged, resulting in a correspondingly short lifetime for the ball bearing. In addition, as a result of the intermittent or jerky application and removal of load on the balls, this known ball bearing operates noisily.
It is an object of the present invention to create an improved ball bearing, which has a long lifetime and functions noiselessly and smoothly without intermittent strains. It is a further object that manufacture of this ball bearing should be economical and relatively simple.